The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
A typical multi-speed automatic transmission uses a combination of torque transmitting devices, such as clutches, dog clutches/synchronizers, or brakes, to achieve a plurality of forward and reverse gear or speed ratios as well as a Neutral and a Park. Selection of speed ratios is typically accomplished by a microprocessor transmission control module that employs various vehicle parameters, for example vehicle speed, and various driver input signals, for example accelerator pedal position, to select the appropriate speed ratios. The transmission then engages a combination of the toque transmitting devices to provide the desired speed ratios.
In order to engage the torque transmitting devices, a typical automatic transmission includes a hydraulic clutch control system that employs a hydraulic fluid to selectively actuate pistons within the torque transmitting devices. Actuation of a piston in turn engages by compression the torque transmitting elements (i.e., reaction discs or plates) within the torque transmitting device to allow torque transmission through the torque transmitting device.
Packaging of the components of the automatic transmission depends on many factors including, but not limited to, the footprint of the transmission housing, the physical connections between the gear sets and shafts which require proper bearing support within the housing, the location of clutches and brakes and their actuators, and the hydraulic fluid routing required to control the clutches and brakes as well as provide lubrication and cooling. Therefore, there is a constant need in the art to solve particular packaging problems with new and useful transmission assemblies.